When working in hazardous environments such as those with toxic, flammable, or oxygen-deficient or rich atmospheres, it is important to keep workers safe and meet regulatory requirements. There are three primary variables that need to be managed associated with the use of direct reading portable gas monitors: the instrument; the sampling system; and the calibration gas used for functionality, bump and calibration tests to prove the monitor is accurately performing to its intended application.
The first variable is the instrument and inaccuracies surrounding its use. These inaccuracies are effectively managed through gas monitor replacement, calibration and maintenance programs used to reduce interference with compliance requirements.
The second variable â the calibration gas system â includes the calibration bottle, the bottleâs valve, regulator and the tubing used to move the calibration gas into the direct reading portable gas monitor. Your systemâs ability to reproduce the target gases concentration consistently depends upon the materials used within the system. Are they compatible with the gas being used within the system, and/ or how were these materials passivated prior to use? Talk to your equipment vendor about the stability and reproducibility of each of the chosen components and their ability to prevent absorption or de-absorption of the minor calibration gas components within the monitoring system. Over time, due to atmospheric conditions, some or all aspects of the sampling system will require replacement in order to prevent service interruptions with your system. An inaccurate sampling system will produce false readings when calibrating, function testing or bumping your system to ensure reliability.
The calibration gas is the component with the greatest potential for variance. The next time you attach a calibration bottle to your direct reading portable gas monitor, benchmark the product you are receiving with products from several other suppliers to determine the variance of manufacturer specifications, stability over a specific shelf life and accuracy of the product. This may be the most critical verification you or your employees perform on a day-to-day basis. Does the vendor have data to substantiate the listed parameters, and how was their published data generated?
In conjunction with the verification of the published data regarding product specifications, how will the calibration gas vendor ensure all the parameters listed above are controlled so you can maintain a safely monitored atmosphere for employees working in a potentially dangerous environment? Is the product you are using considered a low-cost commodity, or is the vendorâs manufacturing process a quality- focused process accredited to a governing body? Are accuracy and reproducibility tested and validated daily? Is the product packaging traceable within their system? Do they effectively review every step of their processes in order to incorporate continuous improvement? In essence, will the calibration bottle you attach to your system to bump or calibrate the direct reading portable gas monitor function precisely the way it should each time it is used so that you can protect worker safety? It is important that you investigate and determine the quality and reliability of the gases and equipment used in your facility.
Calibration gases used for bumping or calibrating direct reading portable gas monitors for industrial hygiene monitoring require the use of certified traceable test gas with a certificate of analysis and expiration date. Ultimately, as the party responsible for safety in your organization, it is your responsibility to establish and uphold a standard with your vendor to ensure the calibration product you are using performs as intended.
Controlling these primary variables in your use of direct reading portable gas monitors is paramount, and each companyâs safety personnel must have a solid understanding of them. Following these guidelines can help you develop true and effective knowledge regarding your calibration gases and the vendor that supplies them and avoid the mindset and related dangers of using âjust another bottle of gas.â
For more information, visit www.Praxair.com or call (800) 225-8247.
